w = Window	{
	x =0, y = 0, width = 300, height = 200,
	titla = "Lua",background = "blue",
	border = true
}

function Window (options)
	if type(options.title) ~="string" then
		error("no title ")
	elseif type(options.width)	~= "number" then
		error("no width")
	elseif type(options.height) ~="number" then
		error("no height")
	end
	_Window(options.title,
		options.x or 0,
		options.y or 0,
		options.width,options.height,
		options.background or "white",
		options.border
	)
end
